Datasheet
AD7634 Data Sheet
Rev. B | Page 8 of 32
PIN CONFIGURATION AND FUNCTION DESCRIPTIONS
PDBUF
PDREF
REFBUFIN
TEMP
AVDD
IN+
AGND
VEE
VCC
IN–
REFGND
REF
D6/EXT/INT
D7/INVSYNC
D8/INVSCLK
D9/RDC/SDIN
OGND
OVDD
DVDD
DGND
D10/SDOUT
D11/SDCLK
D12/SYNC
D13/RDERROR
AGND
AVDD
MODE0
MODE1
D0/OB/2C
D1/A0
D3
D4/DIVSCLK[0]
D5/DIVSCLK[1]
IMPULSE
WARP
BIPOLAR
CNVST
PD
RESET
CS
RD
TEN
NOTES
1. FOR THE LEAD FRAME CHIP SCALE PACKAGE (LFCSP), THE EXPOSED PAD
SHOULD BE CONNECTED TO VEE. THIS CONNECTION IS NOT REQUIRED TO
MEET THE ELECTRICAL PERFORMANCES.
BUSY
D17/SCCS
D16/SCCLK
D15/SCIN
D14/HW/SW
48 47 46 45 44 43 42 41 40 39 38 37
35
34
33
30
31
32
36
29
28
27
25
26
2
3
4
7
6
5
1
8
9
10
12
11
13
14 15 16 17 18 19 20 21 22 23 24
PIN 1
AD7634
TOP VIEW
(Not to Scale)
D2/A1
06406-004
Figure 4. Pin Configuration
Table 6. Pin Function Descriptions
Pin No. Mnemonic Type
1
Description
1, 42 AGND P
Analog Power Ground Pins. Ground reference point for all analog I/O. All analog I/O should be refer-
enced to AGND and should be connected to the analog ground plane of the system. In addition, the
AGND, DGND, and OGND voltages should be at the same potential.
2, 44 AVDD P Analog Power Pins. Nominally 4.75 V to 5.25 V and decoupled with 10 F and 100 nF capacitors.
3, 4 MODE[0:1] DI Data Input/Output Interface Mode Selection.
Interface Mode MODE1 MODE0 Description
0 Low Low 18-bit interface
1 Low High 16-bit interface
2 High Low 8-bit (byte) interface
3 High High Serial interface
5
D0/OB/2C
DI/O
2
In 18-bit parallel mode, this output is used as Bit 0 of the parallel port data output bus and the data
coding is straight binary. In all other modes, this pin allows the choice of straight binary or twos
complement.
When OB/2C
= high, the digital output is straight binary
When OB/2C = low, the MSB is inverted resulting in a twos complement output from its internal shift
register.
6 WARP DI
2
Conversion Mode Selection. See the Modes of Operation section for a more detailed description. Used
in conjunction with the IMPULSE input per the following:
Conversion Mode WARP IMPULSE
Normal Low Low
Impulse Low High
Warp High Low
Normal High High
7 IMPULSE DI
2
Conversion Mode Selection. See the WARP pin description in this table. See the Modes of Operation
section for a more detailed description.